Safety device



May 29, 1945. c os 2,377,070

SAFETY DEVICE Filed Feb. 21, 1944 IINVENTOR HIS ATTORNEY Patented May 29, 1945 UNITED STATES PATENT OFFICE SAFETY DEVICE Ralph Campos, Spreckels, Calif. 7

Application February 21, 1944, Serial No. 523,289

3 Claims.

My invention relates to a safety device for sugar centrifugals, and particularly to a device for locking the sugar displacing plow against movement into the basket of a centrifugal while the centrifugal is in operation.

It is among the objects of my invention to provide a safety device for guarding against injury 'to workmen, and damage to equipment, caused by the inadvertentor accidental movement of the plow into the basket of a sugar centrifugal at a time when the basket is being rotated.

Another object is to provide a locking device which will normally lock the plow of a sugar centrifugal in an inoperative position, and which is moved to release the plow by movement of the sugar discharging valve to its discharging position.

My invention possesses other objects and fea tures of value, some of which with the foregoing will be set forth in the following description of the invention. It is to be understood that I do not limit myself to the showing made by the said description and the drawing as I may adopt variant forms of the invention within the scope of the appended claims.

In the drawing:

Figure 11s a vertical section, partly in side elevation, of a sugar centrifugal having the safety device of my invention attached thereto.

Figure 2 is a fragmental plan view of portions of the centrifugal and the safety device, the figure being drawn upon a larger scale.

In the commercial refining of sugar, a sugar solution containing formed crystals of sugar is delivered into the basket of a centrifugal rotated at high speed. The crystals of sugar are deposited upon the inner wall of the basket, and the mother liquor is separated therefrom by centrifugal force. After crystals have been deposited to a desired depth upon the inner wall surface of the basket and the sugar solution has been separated therefrom by operation of the centrifugal, a sugar delivery valve in the bottom of the basket is opened; and a sugar displacing arm, commonly referred to as a plow, is moved into the basket and manipulated therein to displace the sugar crystals from the basket wall and through the sugar delivery valve,

Since the centrifugal is normally operated at a high speed, the introduction of the plow into the basket while the centrifugal is in operation involves a serious risk of injury to the operator and damage to the equipment. Workmen who thoughtlessly or accidentally move the plow into the basket without first stopping the centrifugal have frequently sustained serious injury such as the loss of a hand or fingers. Even though the operator escapes injury; damage to the equipment almost always results, and, loss due to the delay and expense of repairing or replacing damaged parts is a material item. The safety device of my present invention is intended to guard against the inadvertent or accidental movement of the plow into the basket while the centrifugal is in opera tion.

In terms of broad inclusion, the safety device of my invention comprises a detent mounted in association with the plow. An arm pivoted upon a fixed support adjacent the plow is provided with means interengageable with the detent for normally locking the plow against movement into the basket. The arm is positioned to be engaged and moved to plow releasing position by the discharge valve plate of the centrifugal, when it is moved from its valve closing position to its sugar dis charging position. The valve is opened manually, and can only be opened when the basket is stationary. Movement of the valve plate to its discharge position automatically releases the plow from its normally locked position.

In terms of greater detail, the centrifugal to which my safety device is attached comprises, in general, a basket I secured upon the lower end of a spindle 2 suspended from an over head support 3, and driven at relatively high speed by power applied through a pulley 4. The basket I is positioned within a stationary housing or curb 6. A valve plate 1, commonly referred to as a saw plate valve, normally closes a sugar outlet opening 8 in the bottom of the basket. The valve plate I is movable upwardly from the basket along the spindle 2, and is engaged and supported above the basket by a valve hook 9, secured to a fixed support such as the belt guard l I.

A sugar displacing arm or plow I2 is mounted upon the lower end of a spindle I3 journalled in a post l4. A lever I6 upon the upper end of the spindle I3 is provided for turning the plow about the axis of the spindle. The post I4 is mounted in avertical position upon the free end of an arm 11, which in turn is pivotally mounted as at I 8 upon the curb 6. A shaft journalled in the arm I! is geared to the post I4 by teeth 20; and is actuated by a hand wheel I9 for raising and lowering the plow l2.

While the centrifugal is being operated to separate sugar crystals from sugar solution, the plow is raised to a level above the curb 6, and is swung by means of the arm I! to an inoperative position over the curb, Where it remains idle during the sugar depositing period of operation.

The safety device of my invention comprises a locking arm 2| pivoted as at 22 upon a post 23 secured to the curb 6 adjacent the arm H. A pin 24, or other suitable detent, is secured upon the arm IT in a position to be engaged by a notch 26 in the under side of thearm 2|. The pin 24 and, notch 26 are 50 positioned with respect to the arm that when they are in interengaging relation the arm will be locked in its inoperative position.

The lockinglarm 2| projects inwardly over the basket I to overhang the valve plate 1. When the valve plate 7 is in its normal position closing the sugar discharge opening 8, the locking arm 2| is swung downwardly and held by gravity in looking engagement with the pin 24, thereby guarding against heedless or accidental movement of the plow l2 into the basket When the :valve plate 1 is raised to its sugar discharging .position, as indicated in dotted lines in Figure 1 of the drawing, the lplate engages the inwardly extending end of the arm 2|. As the plate is moved'onto the hook 9, the arm 2| is swung upwardly to the position shown in dotted lines .in Figure 1, thereby causing the notch 26 to disengageathepinld. This-movement efiects a release'of the plow mounting-arm so that the plow l2 may be moved into the basket I and manipulated therein in. the :ordinary manner for displacing thesugar crystals.

The valve plate ,1 is lifted .to its discharge-position manually, and .this can onlybe-done while the basket is stationary. Asa result, the plow is normally heldin theinoperative position until the centrifugal .has .beenstopped and the valve plate ,1 lifted. This insures an efiective guard against introduction-of the .plow into the rapidly rotating basket, either .by .heedlessness :or .accident. At the .same time, themovement of the valve plate to its discharge position automatically releases the plow for its ordinary movements, without requiring a conscious effort or act on the part of the operator.

I claim:

1. In a sugar centrifugal, a rotatable basket having a discharge opening, valve means normally closing the opening and movable to a discharge position, a sugar displacing plow mounted adjacent the basket and movable between inoperative and operative positions outside and inside the basket respectively, a detent carried by the plow, and a locking arm provided with means interengageable with the detent for locking the plow against movement into the basket, said arm being positioned to be engaged and moved to plow releasing position by the valve means when said means is moved to its discharge position.

2. A safety device for sugar centrifugals, having a rotatable basket, a sugar discharge valve and a sugar displacing plow, comprising a looking arm mounted adjacent the plow, and interengageable means carried by the plow and the arm-fornormally locking the plow against movement into the basket when the valve is closed, the locking arm extending .into the path-of movement-of the valve and being movable thereby to plow releasing position when said valve is opened.

3. A safety device for sugar centrifugals, having a rotatable basket, a sugar discharge valve and a sugar displacing plow, comprising a looking arm pivoted adjacent the plowvand having a notch upon its lower edge, a pin carried by the plow and positioned for engagement by the notch for locking the plow against movement into the basket, the arm normallybeing held in engagement with the pin by gravity and extending into the path of movement of the valve and being movable thereby toplow releasing position when said valve is moved to its discharge position.

RALPH CAMPOS. 

